Trigonopterus arachnobas Riedel

Riedel, Alexander & Narakusumo, Raden Pramesa, 2019, One hundred and three new species of Trigonopterus weevils from Sulawesi, ZooKeys 828, pp. 1-153 : 1

7. Trigonopterus arachnobas Riedel sp. n.

Diagnostic description.

Holotype, male (Fig. 7a). Length 2.04 mm. Color of antennae yellowish; legs and rostrum dark ferruginous; remainder black. Body subovate; in profile with distinct constriction between pronotum and elytron. Rostrum long; dorsally with median ridge and pair of sublateral somewhat irregular ridges; intervening furrows with punctures and sparse rows of setae; epistome simple, subglabrous. Pronotum with disk densely, coarsely punctate; interspaces between punctures reticulate, wrinkled. Elytra with striae deeply impressed, intervals costate, subglabrous; punctures each with short, suberect seta. Legs long. Femora edentate. Anteroventral ridges indistinct, simple; anterior surface of femora coriaceous, punctate. Metafemur subapically with stridulatory patch. Abdominal ventrite 1 weakly concave, microreticulate, with coarse punctures; ventrite 5 subglabrous, with subquadrate depression. Penis (Fig. 7b) with sides subparallel in basal 1/2; in apical 1/3 converging in sinuate line forming long, pointed, downwardly curved extension, laterally with sparse setae; basal orifice with well-sclerotized ventral plate; apodemes 2.4 × as long as body of penis; transfer apparatus dentiform, directed basad in repose; ductus ejaculatorius with indistinct bulbus. Intraspecific variation. Length 1.98-2.04 mm.

Material examined.

Holotype (MZB): ARC3014 (GenBank # MK260543), S-Sulawesi Prov., Tanah Toraja, Rantepao, Gn. Karre (= Gn. Wokim), 02°59.013'S 120°02.251'E, 1423 m, sifted, 06-V-2013. Paratypes (MZB, SMNK): 2 exx, ARC3015 (GenBank # MK260546), same data as holotype; 2 exx, ARC6024 (GenBank # MK260544), ARC6025 (GenBank # MK260545), Tanah Toraja, Rantepao, Gn. Karre (= Gn. Wokim), 02°59.021'S 120°02.523'E, 1456 m, 06-V-2013, sifted.

Distribution.

S-Sulawesi Prov. (Tanah Toraja). Elevation 1420-1460 m.

Biology.

In leaf litter of montane forest.

Etymology.

This epithet is based on the genus name Arachnobas Boisduval and is treated as a noun in apposition. It refers to the superficial resemblance of the species´ habitus.

Notes.

Trigonopterus arachnobas Riedel, sp. n. was coded as " Trigonopterus sp. 517".